Surveying instrument



s. R. SEIBERT. Surveying Instruments.

No. 25,678. Patented Oct. 4, 1859.

' 4/ VEIY 7'0 1? UNITED STATES PATENT OFFICE.

SAMUEL R. SEIBE'RT, OF MUNISING, MICHIGAN.

SURVEYING INSTRUMENT.

Specification of Letters Patent No. 25,678, dated October 4, 1859.

To all whom it may concern:

Be it known that I, SAML. R. SEIBERT, of Munising, in Schoolcraft county, State of Michigan, have invented a new and Im proved Method of Constructing Surveying Instruments; and I do hereby declare that the following is a full and exact description of the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon, making a part of this specification, in which Figure 1 is a perspective general View; Fig. 2, the base view of lower Plate No. 1 in Fig. 1; Fig. 3, side view of Ys or telescope supports; Fig. 4, a vertical view of We or telescope supports; Figs. 5 and 6, diiferent base views of clamping pinion; Fig. 7, side view of clamping pinion.

The nature of my invention consists in constructing the supports of the telescope in such a manner as to allow it to be revolved upon its axis and be brought to bear upon any object appearing between the zenith and the horizon. The construction also admits of the use of a magnetic needle and of an improved sextant in principle the same as invented by \Villiam Burt. This mode of supporting the telescope makes it an important check upon the sextant, for instance, in ascertaining by the sextant the latitude of any position. The image of the sun is brought upon the plate of the limb H, Fig. 1. It should be also upon the cross hairs in the telescope at the same time, so that when the sextant reads the meridian passage of the sun the telescope can be used to ascertain its correctness and the altitude read by the vertical circle. It can also be used at night in connection with the moon and his culminating stars, producing the same results. In short the combination of magnetic needle sextant and telescope furnish unmistakable guides for the running of lines, determining of latitudes, determining time and the variation of the magnetic needle from a true meridian. The clamping pinion by which the different limbs are moved and clamped will be found fully described and referred to by letter.

To enable others skilled in the art to make and use my invention I will proceed to describe its construction'and operation.

I construct the lower Plate No. 1, Fig. 1, also shown at Fig. 2 in the accompanying drawing, so as to admit of the Ys or sup ports of telescope of which Figs. 8 and 4 are representations, being permanently attached to said lower plate. As the lower extremity of said Ys or supports have what is termed a wide base, it will be perceived that when they (the supports of telescope) are attached to the lower plate they form an immovable construction of each support and when combined by the axis A of telescope R in Fig. I obtain a permanency seldom, if ever, found in portable instruments. I construct my supports or Ys, Figs. 3 and 4, so as to throw the center of upper part of said Ys or supports suificiently beyond the upper Plate B in Fig. 1 as to admit of the telescope when resting in said Ys or supports to be revolved on its axis from a horizontal to a vertical position. I construct my clamping pinion as represented in the accompanying drawing, in Figs. 5 and 6 as base views and Fig. 7 as a side view. The center piece 0 in Figs. 5, 6, and 7, to the lower extremity of which are permanently attached the cogs L, can be constructed round and a steady pin D in Fig. 5 permanently soldered to sliding milled head E, Fig. 7 It can also be angular, so as to pre vent it (the said sliding milled head) from turning without carrying this center piece C with it. The upper extremity of this center piece C in Figs. 5, 6, and 7 has a thread out upon it, 011 which is screwed the milled bur F, Fig. 7. By screwing this milled bur F upon the sliding milled head E, Fig. 7, it forces the sliding head upon or against the plate G Fig. 7, in which cogs are also cut or which represents part of the circle upon which the limb is usually slid. H and I, Fig; 1, represent the segment of a circle (usually called the declination arc and divided into parts of degrees) and limb as they are generally constructed. The clamping pinion is not visible, as it appears behind said arc H. This clamping pinion can be applied to any instrument or place where a limb with vernier or index attached is to be slid or moved for the purpose of reading different angles.

What I claim as my invention, and desire to secure by Letters Patent, is-

1. Constructing the Ys, or supports of the telescope in a surveying instrument as set forth.

2. Also constructing a clamping pinion in the manner and for the purposes as herein described.

SAML. R. SEIBERT.

\Vitnesses:

JAS. E. McCLEEs, WM. HINKLE. 

